My surveillance system (Zoneminder) "records" movements by capturing screenshots. Putting these screenshots together in order and running through them gives the same effect as watching a recorded video.

When a Zoneminder event is exported, you basically get a folder with these screenshots:

For archiving purposes this is OK, but not if you want to send this to someone. So I needed to find a way to create a video file or an animated image/gif from these images.